Various devices have been used to test leakage of various filters employed in bio safety cabinets, pharmaceutical clean rooms, animal testing laboratories and nuclear environments. These devices have included photometers used in conjunction with aerosol generators to measure how well a filter is performing. Typically, an aerosol with a known concentration is introduced before or upstream of the filter and the photometer is operably connected to the downstream side of the filter to measure any leakage of the aerosol through the filter. Photometers typically utilize forward light scattering to measure any leakage of aerosol through the filter being tested.
Prior known devices can test both upstream and downstream samples. To test the upstream sample, a conduit is typically connected to a base unit with the open end of the conduit deployed upstream of the filter being tested. To test the downstream sample, prior known devices have used a probe operably connected to the base unit. The probe is deployed on the downstream side of the filter and conveys the test sample back to the base unit to be processed to determine any leakage of aerosol through the filter.
Prior known systems have several significant limitations. One such drawback is the inability of the prior known devices to change the mode of operation of the testing system without directly interacting with the base unit. For example, the test system cannot be changed between upstream sampling and downstream sampling without manipulating controls located on the base unit. Also, prior known systems do not allow an operator to enter information regarding a filter being tested from a location remote from the base unit. Further, prior known devices do not allow the testing unit to readily test a filter where the test sample (typically aerosol) was unstable. Further, prior known systems do not permit a residual test sample located in the probe and/or base unit to be automatically exhausted when the testing system changes between testing an upstream sample and downstream sample. Moreover, prior known systems have not been configured to detect when the probe is connected to the base unit and alter the operating capabilities of the testing system when the probe is connected to the base unit.